Animal Models Of Hematopoietic Growth Factor Excess

Administration of an HGF to a normal animal superimposes an acute excess of circulating factor on otherwise normal hematopoiesis, potentially mimicking factor-driven emergency hematopoiesis. Numerous preclinical evaluations of this type have been done, and only some are summarized in this chapter. A particular advantage of this approach is its flexibility for comprehensive testing of the in vivo effects of combinations of multiple different factors, including enabling a range of scheduling issues to be evaluated.

Genetic models of HGF overproduction have the advantage of durability and provide additional information about the effects of chronic long-term exposure to the factor (Table 7). When the model is based on germline transgenesis, the model is able to be propagated, and populations of uniformly affected animals can be generated for study. Genetic approaches are particularly useful for evaluating the effects of excess factor production in vivo when there are limited amounts of factor available for direct administration and for defining the toxicity of long-term factor exposure.